By AndyW 04/2004

Why? - two issues here, wheel alignment is going to affect the bike's handling (surprise!) and alignment of the primary and rear sprockets will affect wear of the chain and sprockets.

As the handling of the bike is clearly more important than wear and tear of the chain/sprockets it's alignment of the wheels that should be checked but keep an eye on chain tension!. That said it is a good idea to check that the sprockets are aligned as any misalignment could indicate problems else where (e.g. sprocket mounting)

Indications of there being a problem might be a tendency for the bike to pull to the left or right on flat roads (no cambre), apparent better (worse) turn in left or right, unusual tyre wear pattern etc.

The alignment marks on the swingarm can only be relied upon as a rough guide, with accuracy being different from bike to bike, so here's a few ideas on doing the job accurately.

Ponch Villa 04/2004
The way I learned this procedure 30yrs ago was to take a piece of kite string about twice the length of the bike.
The bike is on a center stand, straight and level.
1) tie one end around the FRONT of the FRONT tire approx 6" off the floor.
2) run the string under the bike and through center stand to the BACK of the REAR tire at the same height off the floor.
3) loop the string completely around (360degrees) the BACK of the REAR tire at that level.
4) run the string back to the front on the OTHER SIDE of the bike.
5) tie it off around the front of the front tire at the same height as before.
6) center the front wheel by looking down the string and evening the distance between the string and BACK of the FRONT tire as it spreads out to the wider rear tire.
7) rotate either tire minimally to keep tension on the string.
8) adjust the chain for proper slack.
9) laying on the ground, from behind the bike, you can eyeball the string as it touches each tire front and back and determine EXACTLY how true the tires are lined up with each other.
10) adjust the REAR wheel to achieve a PERFECT ALIGNMENT.
11) take note and RECORD any deviation of the factory markings on the swing arm.
12) future adjustments should prove that you can now follow the marks taking into account your recorded deviations if any.
12) don't forget to lock everything down.
13) check to verify that the chain is also centered on the sprocket.
14) having done all this you will now have something more to listen for when you ride.
15) the chain/sprocket alignment has different sounds for how true they are meshing.
16) you will now be listening for how quiet you can make your chain...disappear!
 

Quick, accurate, and relatively cheap wheel alignment - By Bayouboy 01/2004

In the beginning I used the swingarm graduation marks to align the rear wheel with the front. As most of us know from various posts on the forum, these marks are not accurate on all bikes and better methods are advised. The last couple times I aligned my rear wheel I used the string method which BTW is covered in this months Motorcyclist mag's "How To" section also found here. The string method definitely works but it can be a bit of a bitch in that you have to view along the string to be sure it doesn't bend at all on its way from the back wheel to the front, see pic. It has taken me well over 30 minutes to get acceptable results using this method and once when I was a bit tired I had to give up and finish the job later after resting a while. So I've been thinking about a better way to do this.

Well I saw these really cheap ($15) carpenter's laser levels on line the other day so I ordered a pair with the hopes of using them to align the rear wheel. It worked out rather well. Just attach them to the rear wheel with elastic cords and turn them on. Then I hung a string with a nut from the center of the front wheel to act as a plumb bob and placed a board behind to show the red dots. If the laser levels were high quality the rear wheel would be properly aligned when the red dots were equidistant from the plumb bob. In my case however the laser levels suck (I guess you get what you pay for, lol) and I have to offset the midpoint mark a bit from the plumb bob for correct alignment. It is however easy to correct for this error in alignment of the laser relative to the level and get the proper results. Now I can stay back by the rear wheel and adjust the chain tensioning bolts and watch the red dots move. This method is much much easier than the string method to get simultaneous correct chain tension and wheel alignment.

Bayouboy 11/2003
What's more important aligning the rear sprocket with the front sprocket or aligning the rear wheel with the front wheel??

In a perfect world I guess the above two actions would automatically happen together since the front wheel and sprocket should have parallel rotational axes when the bike is pointed straight ahead. But if the forks are off a little or the motor got mounted in the frame a hair crooked or whatever they might not be.

I found some devices to aid in aligning the chain between the the two sprockets. They say this is good to avoid extra damage to sprockets and chains caused by misalignment. But I think I would rather avoid the extra damage to my face that could be caused my misalignment of the two wheels, so still looking for a wheel alignment aid.

TLtoM2 09/2003
I align my rear wheel by raising the back end off the ground and pointing the front straight ahead. using two pieces of box section aluminium that are at least a foot longer than the wheel base of the bike, place the box aluminum longitudinally under the bike...support the pieces with some wood so the centre of the aluminum is running along each side of the profile of the rear tire. support the front of the beams with more wood and make sure they are level. the two beams will now be pointing in the direction your rear tire is aligned to. when properly set up you should be able to measure the same distance between inner edge of the aluminum sections and the outer edge of your front tire.

You can use string or wood for this measurement also, but I like the box section aluminum because it is more likely to be dead straight.

NevadaSV1000S 09/2003
There is a very inexpensive tool on the market that is made specifically for this job. It attaches to your rear sprocket with a clamp and there is a 12" long steel rod (that can be shortened if needed) that runs down the length of chain. You basically site down the rod as it runs between the links....very easy to use. Check your local dirt bike store, I don't think it has caught on to the street riders yet

AndyW - that sounds like a useful addition to the toolbox but remember wheel/tyre alignment is the crucial thing.  Sprocket alignment probably takes more priority for the off roaders as wheel alignment (within reason) isn't going to make so much difference on dirt.

Jimbo77 09/2003
(re Motion Pro sprocket alignment tool) I'd be more concerned with aligning the front and rear tires, and not so much on the sprocket alignment. Tire alignment can be done with two straight edges running from either side of the rear tire toward the front. Make sure the distance from the front tire to the straight edges is equal on both sides. Odds are, if your tires are aligned, you'll get better wear, a more true driving line, and your sprockets will most likely be okay also. I've aligned the tires for years when adjusting the chain, but I've never given a second thought to the sprockets.....
Finding a straight edge is difficult at best, while being inexpensive. I've solved both problems. I use a piece of wood about 6' long, with a small nail tapped in each end. Then I run a piece of string tightly between the two nails. Instant Straight Edge!

TLRMan 09/2003
If you got someone in the machine shop trade, you can have this made up.
It's a bar of Alum, with 2 cones mounted on rods. One rod is fixed, and the other is allowed to slide along a slot cut into the bar. Set your chain tension, and then put one of the cones into the swingarm pivot, and the other into the axle, sliding it until is sits perpendicular, tighten a screw that sets it, then go to the other side of the bike and compare the spacing...

AndyW: really accurate way of checking that the wheel is 'square' in the swingarm which in theory should mean that it is true with the front wheel - in practice this may not be the case.
I also read somewhere about making up a pair of pointers, round metal or wood items the right diameters to slide into the swingarm and axle holes - then measure between them.
 

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